Drilling apparatus



Jan. 6, 1948. w. w. PAGET u I2,434,120

' QRILLING APPARATUS Jan 6, W W PAGET DRILLING APPARATUS Filed March`1o, 1944 5 sheets-sheet 2 wig' W am W m mw, ,7 M r O E Nv MJ j wm. *M 1uw nu wx@ R W um, Nw? ,QA um, N% m www, Q u @w Q mw o Nm m v wr/)rw/r f.r rr ,NMr/rMH/ A d WM Q mi m Q bm www www mx mm? :Hl mw@ nHr Hlm. 9m lmw Sw Q mw mmm Q QQ .Q um Q. W

Jan. 6, 1948. w, PAGET 2,434,120

DRILLINc. APPARATUS Filed March I, 1944 l 5 Sheets-Sheet 3 Y y U-...

DRILLING APPARATUS Filed March l0, 1944 5 Sheets-Sheet 4 w. w. PAGET2,434,120A

Jan. 6, 1948.

W. W. PAGET DRILLING APPARATUS Fil'ed March l0, 1944 5 Sheets-Sheet 5P05/Cf..

15e @en for fifty Patented Jan. 6, 1948 DRILLING APPARATUS Win W. Paget,vMichigan City, Ind., assignor to k.l'oyYManuf-acturing Company, acorporation of Pennsylvania Application March 10, 19421, Serial No.525,869

(Cl. .Z55-47;)

24 Claims. 1

This invention relates to drilling apparatus, and more particularly vtoimprovements in feed control means for drilling apparatus ofthe rotarytype.

In drilling hard material, such as rock,'fb.y rotating a bit impregnatedwith diamonds or borts while it is in engagement with lthe material tobe drilled, and feeding the bit vtoward the work as the material is cutaway, there may be, if the bit is fed too rapidly, la binding of Vthebit, resulting in an overloading of the bit Irotating motor, a burningof the bit vor a fracture of some part of the drilling apparatus. Some`of these diliculties may be encountered, vregardless of the type ofbit, if excessive feeding pressures are used. By controllingautomatically the rate of feed Ain accordance with the resistance to-rotation of the drill bit, it is possible to Vprevent the undesirableresults above mentioned from toccurring, and at the same time tomaintain the feeding pressure that is necessary to obtain the fastestdrilling speed.

The invention from one aspect may comprise a drill feeding meansembodying relatively rotatable, mechanically interengaged feedingelements for effecting feed of a drilling implement, to-r gether withmeans for automatically controlling the relative rotation of the feedingYelements .in accordance with the resistance -to rotation `of vthedrilling implement, to regulate the yrate of feed. Desirably, theinvention may comprise a vdrill feeding means including a torque motoryfor -providing a feed-effecting force, and means automaticallycontrolled vby load changes on the drilling implement to control thetransmissionof the force provided by the torque motor to effect afeeding of the drilling implement. Thefeeding means may compriserelatively rotatable feed screw and nut elements and a friction device,controlled by the load changes on the drilling implement, forautomatically controlling the relative rotation of the feeding elements.The friction device may desirably be in the form of a brake and maycontrol rotation of either the Yfeed screw or the feed nut. In apreferred embodiment the brake may Lbe applied to resist rotation of theelement rdriven by the torque motor, thereby reducing the relativerotation between the feed elements and decreasing the rate of feed.Again, the brake may be normally applied Ato hold one of the feedelements against rotation While the other element is rotated by thetorque motor, and, on overloading of .the drilling implement, the brakemay be automatically releasedso thatfthe normally braked element vmayrotate, therebyreducing the relative rotation between the elements anddecreasing the -rate Aof feed. While reaction of the V.motor casing isapreferred source of feed control-ling force, lit `will be understoodthat 'rela'- tive rotation between parts in the drive of the bit, orvariations in the 4power demand .of an electric bit-rotating motor, Vmaybe caused :to effect feed control without departing from-my invention inits .broader aspects. In .different embodiments .of the invention, themotor for rotating .the ydrilling implement, as well as .the torquemotor, may -be caused either to move along a, guide :member with thedrilling :implement xduring feeding .of the latter or may beheldstationary while .the drilling implement is 4*fed relative itc Vitswork.

It is .therefore an object of this invention to provide an improveddrilling .apparatus having improved feed control means embodied therein.Another object is fto .provide in a rotary .type drilling apparatus yanimproved feed control means operative:tocontrolithe `feeding of thedrill bit .in accordance with Ythe .resistance to'rotation of the bit.Still another object isV to provide an improved feed `control means .fora rotary type drilling ..apparatus, .said feed ,control means 'op-Yerative in vaccordance with :the load on the bit rotating motor forvaryingautomat'icallyJthe'drill feed. Another object .is to providerelatively rotatable feeding elements for .a bit rotating motor, andvfeed control-means operatively connected with the bit rotating motorand actuated thereby as the load on the motor changes for altering theresistance vto rotation zof oneofsaid elements. Still another lObjectis-to .provide improved feejding :means for a drilling implementof therotary type, said feeding means including relativelyrotatableffeedingelements operative on relative rotation to effect feed,and means responsive yto Vthe resistances to rotation of said drillingimplement `for controlling `the relative rotation between said feedingelements. Yet .another object sis vto rprovide relatively rotatablefeeding elements for adrilling implementof the rotary type, and meansVforcontrolling the relative rotation between said elements, saidcontrolling "means including means for resisting the rotation of one`ofsaid feeding elements whereby the rate. of relative rotation lbetweensaid lelements is reduced,.and means for actuating the resistingzmeansto resist the rotationof the feeding element when the `resistance torotation of the .drilling implement exceeds `a .predetermined amount.yAnother object is fto ,provide relatively rotatable Vfeedingelementsgfora drilling implement :of y.the-.rotary type,'withcontrolling means'v vention will, however, hereinafter more fullyap-l pear.

The present application is a continuation-inpart of my copendingapplication Serial No.

368,692, led December 5, 1940, now abandoned.

n the accompanying drawings there are shown for purposes of illustrationseveral forms which the invention may assume in practice.

1n these drawings,

Fig. 1 is a plan View of a drill mechanism having incorporated thereinone illustrative embodiment of the invention.

Fig. 2 is a side elevational view, with parts broken away, of the drillmechanism shown in Fig. 1.

Figs. 3 and 4 taken together constitute an enlarged view in longitudinalvertical section through the drill mechanism shown in Figs. 1 and 2 Fig.5 is a transverse sectional View through the drill mechanism and takenon the plane of the line 5 5 of Fig. 3.

Fig. 6 is a detail sectional view taken on the line 6-6 of Fig. 3.

Fig. 7 is a transverse sectional view taken on the line 1-1 of Fig. 4.

Fig. 3 is a transverse sectional View taken substantially on the line8--8 of Fig. 3.

Fig. 9 is a fragmentary sectional view taken on a plane corresponding tothe plane of Fig. 3, and showing a modication of the invention.

Fig. 10 is a cross sectional view taken substantially on the plane ofthe line Ill-I9 of Fig. 9.

Fig. 11 is a longitudinal sectional view showing another modiiication ofthe invention.

Fig. 12 is a cross sectional view taken substanu tially on the plane ofthe line I2-I2 of Fig. 1l.

Fig. 13 is a side elevational view of a drilling apparatus, with partsshown in longitudinal section, having still another modication of theinvention embodied therein.

Fig. 14 is a cross sectional view taken substantially on line I4--I4 ofFig. 13. f

Fig. 15 is a longitudinal sectional view showing the rear portion of thefeeding means for the drilling apparatus shown in Fig, 13.

Fig. 16 is a cross sectional view taken substantially on line I--I ofFig. 13.`

In the illustrative embodiment of the invention shown in Figs. 1 to 8inclusive, a rotary type drilling apparatus generally designated I ismounted on a supporting and guiding structure, generally designated 2,and has associated therewith drill feeding means generally Vdesignated 3and feed control means generally designated 4.

The drilling apparatus I includes a bit rotating motor 6 carried by arear head member 1 which is slidably guided on the supporting andguiding structure 2 in a manner that will shortly be described. Themotor is herein of the high speed electric type and includes a casing 8provided with front and rear heads 9 and I0 held in assembled relationwith respect to the casing by usual tie bolts II. The motor has a usualeld I3 and an armature rotor I4, the latter having a shaft I5 which isjournaled in bearings I3, I9 suitably supported in the motor heads.Attached to the forward end of the shaft I5 is a chuck I8 for receivingthe shank of a hollow dri11 rod I9 which carries a drill bit20. The rearmotor head IB has a rearward cylindric projection 22 mounted for limitedrotation in ball bearings 23 supported within a bore 24 formed in thehead member 1. The bearings 23 are retained in the bore 24 by means of aretaining ring 25 secured, as by screws 23, to the head member 1; andthe cylindric projection is held against axial displacement with respectto its bearings by means of an end plate 21 secured, as by screws, tothe projection 22. Extending through a bore in the shaft I5 is a liquidVconducting tube 28 which is threaded at its rear end within a member 29secured to the rear head member 1, and cleansing liquid is suppliedthrough a passage 3E) in the member 29 to the tube 28 where it isconducted to the hollow drill rod and through the latter to the drillholel Attached to the rear end of the shaft I5 is a member 32 fittingclosely around the tube 28 and having an annular flange engaging anannular flange on the end plate 21 to provide a seal preventing anycleansing liquid escaping around the end of the tube 28 from passing tothe bearings I3 in the rear motor head and to the motor windings. Apassage 33 in the member 29 connects the space surrounding the rear endoi the tube to a vent passage 34 so that any liquid escaping around theend of the tube may drain away. The structure so far described, exceptfor the rear head member 1, is similar to that disclosed in a copendingapplication to one Carl E. Dittmer, Serial No. 328,737, now matured intoPatent No. 2,296,273, patented September 22, 1942, and furtherdescription of the same herein is accordingly unnecessary. The rear headmember 1 is provided with a depending portion 36 that projects within atrough-like member 31 of the supporting and guiding structure 2, asshown in Figs. 3 and 5. Formed on the sides of the depending portion areanges 39, 39 which are slidably received in grooves 49, 49 in the sidesof the member 31 for guiding the drilling apparatus as it moves alongthe supporting and guiding means.

Referring to the drill feeding means, it will be noted that there isprovided a feed screw 42 extending longitudinally through thetrough-like member 31 in parallelism to the grooves 49, and the feedscrew is journaled at its forward end in a plate 43 extendingtransversely ofthe member 31 and at its rearward end in a housing 44, asshown in Figs. 3 and 4. The plate 43 and the housing 44 are held infixed positions to the ends of the member 31 by tie rods 46. Keyed tothe feed screw at its rearward end is a worm wheel 41 meshing with aworm gear 48 that is keyed to a shaft/49 extending transversely throughthe housing 44 and journaled in the sides of the housing as shown inFig. 7. Attached to a side of the housing, as by screws 53, and inalinement with the shaft 49 is a motor 5I, shown herein as an electrictorque motor, having its rotor attached to an end of the shaft 43projecting through the side of the housing. A switch box 52 is attached,as by screws 53, to the rear end of the housing 44 and contains a switchhaving a control handle 54 for controlling the flow of electric currentthrough lines 55 and 53 to the motors 6 and 5I, respectively. The feedscrew extends, as shown in Fig. 3, through the depending portion 39 ofthe head member 1, and a feed nut 58 having a head 59 engaging surfaceson the head member 'l is clamped firmly to the head member in threadedengagement with the feed screw by a clamping nut 39. AS the feed nut isheld against bodily and rotative movements relative to the head mem-lber 1 there will be, during rotation of the feedv screw by the' motor 5|through the worm gear 48 andthe worm wheel '41, a feeding or aretractive movement of the drilling apparatus relative to the suppertingand guiding structure 2. Formed on the member 31 of the supporting andguiding structurels a swivel plate 82 adapted for clamping in the saddlemounting of a conventional rock drill support. With the drillingapparatus supported at the face of material to be drilled and a rotationof the feed screw in a direction to effect movement of the ldrillingapparatus toward the material, there will be, on engagement of the ma-Aterial by the drill bit and on rotation of the drill bit by the motor 6,a drilling of the material. If the drill bit is unable to cut its'way asrapidly as the drilling apparatus is fed toward the material there willbe a binding of the bit with a resulting increase in the load on the bitrotating motor, and if the load is rincreased sufficiently the bitrotating motor may be stalled or the bit may be damaged. To preventstalling of the motor or damage to the bit, there is provided the feedcontrol means generally designated 4.

The feed control means e, as shown in Fi'g- 3, includes a sleeve 84'surrounding the feed screw and having splines 65 slidably` fittingwithin Igrooves S6 formed in the feed screw, as shown in Fig. 8, so thatthe sleeve is held against rotation relative to the feed screw but ispermitted to move longitudinally thereof. The sleeve 64 is rotatablysupported at its front and rear ends, respectively, within an opening inthe front wall of a recessed member S8 which is attached to the headmember 1, as by screws 69, and within an opening in a cover plate 10attached to the recessed member, as by screws 1|. The sleeve is heldagainst bodily movement relative to the head member and longitudinallyof the feed screw by split rings 12, 12 engaging the recessed member |58and the cover plate 10. Held to the sleeve 64 are friction elements inthe form of brake disks 13 interleaved with other friction elements inthe form vof brake disks 14 held within the recessed member 68 againstrotation relative to the latter in any suitable manner. Surrounding thefeed screw is a shipper 'ring 15 having lprojecting, members 16extending through openings in the front wall of the recessed member 88into engagement with one of the brake disks. Formed in the head member 1i's a chamber 11, and extending through this chamber transversely of thedrilling apparatus is a rod 18 having its ends supported by the sidewalls of the chamber, as shown in Fig. 5, A shipper arm 19 is pivotallysupported at one of its ends 4by the rod 18 and at its other end isprovided with forkeclarms 80 having projecting portions 8| Vfittingwithin an annular groove 82 in the shipper ring 15. The shipper arm isprovided between its endsl with an elbow-like bend 84, and fixed to theend plate 21 of the drillro-l tating motor is a cam device 85 having acam surface 86 for engaging the elbow 84 and forcing the shipper arm tovswing about its pivot and effect a pressing together of the brake disksthrough the shipper ring when the drill rotating motor is caused torotate in the bearings 23 in a countereclockwise direction as viewedl inFig. 5. Threaded into an opening in the end plate 21 is'a ypin 88 havingits outer `end projecting a short distance from the rear surface of theplate, and a plunger 89 is reciprocable within a sleeve-shaped member 90which is threaded into an opening in a side of the head member 1, andtheplunger is 6 jectig portion of the pin 88. The force of the spring 95|is such that it prevents the motor'eld I3 and casing 8 from turning inthe bearings 23 ih a countereclockwise direction as viewed in Fig.

. 5, Vduring norma1 drilling operations, but on ine crease` of the motorload above a safe limit the motor casing turns against the force ofspring-9| and causes the cam device 85 to swing the shipper arm 19 aboutits pivot and effect an application of the brake disks, slowing down orstopping the drill'fee'd.

The mode of operation is 'as follows: The swivel plate 32 of the'-supporting and guiding means is clamped ih the saddle mounting of adrill support at the face .of the work and the 'switch control handle54fis operated to close the switch and sup'- ply current to the drillrotating motor 6 and to the drill feeding motor 5|. The motor 5| is runin a direction to cause the feed screw 42 to be driven through the wormgear 48 and the worm wheel 41 in such 'a way that the drilling apparatuswill be fed` toward the work due to the engagement of the non-rotatablefeed nut 58 with the feed screw. As the drill bit is moved intoengagement with the work, drilling will take place, and if the load onthe drill rotating motor is not too great the body of the motor will beheld against rotation in the bearings' 23 by the spring 9| forcing theplunger 89 against the pin 88. If the feeding pressure is such that thedrill bit 20 is unable to cut its way without increasing abnormally theload on the bit rotating motor, there will be a turning ofthe motorfinthe bearings 23 against the force lof spring 9|, 'and the cam device 85will effect a swinging of the shipper arm 19 in a direction to Cause thebrake disks 13 and 14 to be pressed together and slow down or stop therotation of the feed screw in a feeding direction.

' There is shown in Figs. 9 'and 10 a modincation of the invention inwhich a feed nut 95 is rotatably suppo'rted at its front end by arbearing 96 carried by a depending portion 91 lof the lhead member 1,and rotatably supported at its rear end by a bearing 98 carried by thecover plate 10. The feed nutthreadedly engages a feed screw l 00, andvsurrounding the feed nut are friction elements 0| held against rotationrelative to the nut 'and interleaved with friction elements `|02 whichare held within the recessed member B8 against rotation relative to thelatter, in any suitable manner. A shipper ring |03 surrounds the feednut and has lingers |04 projecting through openings in the member 68into engagement with the friction disks. A spring |05 surrounding theforced by a spring 9| against theside of .the pro- 75 feed nut actsbetween the depending portion 91 and the shipper ring to urge the latterin a direction to press the friction elements into engage-'- ment witheach other. Pivotally supported within the chamber 11 on a rod |06 is anarm |01 vhaving forked portions |08 which carry projecting portions 09extending into an annular groove ||0 in the' ring |03. The arm |01extends above its pivotal supporting rod, "and the upper portion of thearm is engageable by the cam device and caused to swing in a clock-wisedirection by the latter when the drill rotating motor is overloaded. Itwill be seen that the feed nut' will be held against rotation by thefriction elements during normal drilling, but, as the drilling loadsbecome excessive, the arm |01 will be swung in a direction to force theshipper ring out of engagement with the friction elements vso that thebraking force is removed, or at least decreased, and the feednut'rotates with the feed screw, decreasing or-s'topping thefeed. Y Y YIn Figs. 11 and 12 there is shown'a modifica-l tion in which a feedscrew ||5 is supported by a guide member i6 and held against rotationrelative to the latter. Slidably mounted on the guide member He is ahead member, generally designated H1, to which the drill rotating motor6 is operatively connected, as described in the first form `of theinvention. The head member ||1 has a depending section ||8 rotatablysupporting a feed nut ||9 in threaded engagement with the feed screw||5. The feed nut is provided with teeth |20 which mesh with the teeth-of a worm |2| keyed to a shaft |22 supported by and extendingtransversely of the head member ||1. Fixed to the shaft |22 is a gear|23 meshing with a gear |24 fixed to a shaft y|25 supported by the headmember. Also connected to the shaft |25 is a bevel gear |21 meshing witha bevel gear |28 fixed to one end of the power shaft |29 of a motor |30secured, as by bolts |3l, within a chamber |32 in the head member ||1.Surrounding the power shaft |29 adjacent its other end are frictionelements |34 held against rotation relative to the power shaft andinterleaved with friction elements |35 which are held against rotationrelative to the head member. A plate member |36 is provided withprojecting portions |31 which are adapted to press the friction elementstogether when the plate member is moved in a rearward direction. A lever|38 pivotally supported at |39 is adapted to be swung by the cam device85 to apply pressure to the plate |36 to force the plate member in adirection to press the friction elements together when the drillrotating motor is overloaded. During normal drill loads, the motor |30operates to drive the feed nut ||9 through the bevel gears |28, |21, theshaft |25, the gears |24, |23, the Shaft |22, the worm gear |2|, and theteeth |20 on the feed nut. When' the drill rotating motor becomesoverloaded, it rotates slightly relative to the head member ||1 andcauses the cam device 85 to act on the lever |38 to force the platemember |36 in a direction to press the friction elements together. Therotation of the power shaft |20 is then resisted and caused to slowdown, thereby reducing the rate of rotation of the feed nut.

In'Figs. 13 to 16 there is shown another modi* cation in which asupporting and guiding member |40 is shown ported and held in a xedposition, as by bolts |42, operatively connected to the head member in amanner similar to that described in the first form zof the invention,but projecting rearwardly from the head member, is a drill rotatingmotor 6. In this case, a shaft |i4 extends thr-ough the head member |4|and axially through vthe rotor of the drill motor. Grooves |45 formed inthe shaft are adapted to receive keys fixed to the rotor so that theshaft will be caused to rotate with the rotor but may move axiallyrelative to the rotor. As in the rst form of the invention, a feed screwM6 is rotatably supported by the member |40 and is caused to be rotatedthrough a worm wheel 41 keyed to the feed screw and mesh-v ing with aLworm gear 48 which is fixed to a shaft 49 driven by a motor 5|. A switch52 having a manually operated lever '5 is adapted to control the supplyof current to the motors 6 and 5|.

Surrounding the feed screw is a sleeve-shaped member |50 having splinesfitting within grooves in the feed screw so that the sleeve member mustturn if the screw turns. The sleeve'mernn ber is rotatably supported atone end in the wall of a recessed member |52 attached to a de endn onwhich a head member |4| is suping portion |53 of the head member |4|,Vand is rotatably supported at its other end in a cover plate |54attached to the recessed member, as by screws |55. Held to the sleevemember are friction elements |56 interleaved with friction elements |51held within the recessed member against rotation relative to the latter.A shipper ring |58 is provided with projecting portions extendingthrough openings in the recessed member for pressing the frictionelements together, and an arm |60 is pivotally supported by the headmember |4| and is adapted to be swung by the cam device in a directionto move the shipper ring toward the friction elements.

A feed nut |62 threadedly Vengages the feed screw at the forward side ofthe head member |4| and is clamped within an opening in a drill feedmember |63 which is provided, as shown in Fig. 16, with guide flanges|65 slidably received in guideways |66 in the member |40. The member |63is provided in its upper portion with a recess which contains a bearing|61 rotatably supporting the shaft |44 and adapted to exert rearwardfeeding forces on the shaft |44, and a thrust bearing |68 which actsagainst a collar |10 threaded on the shaft for forcing the latter in aforward feeding direction. Carried by the shaft |44 is a chuck |1|adapted to receive a drill rod |12 which has fixed to its outer end adrill bit |13.

As the feed screw is rotated by .the motor 5|, the feed nut moves alongthe feed screw and causes the drill rod to be fed by reason of itsconnection to the feed member |63. If the load on the drill rotatingmotor becomes too great, the motor rotates relative to the supportmember |4| and actuates the arm |60 through the cam device 85, pressingthe friction elements together and resisting rotation of the Vfeedscrew.

As a result ofV this invention there is provided an improved feedcontrol means for a rotary type drilling apparatus. It will be notedthat as a result of the improvedfeed control means the rate of drillfeed may be gradually reduced until the feeding of the bit is completelystopped, when the load on the bit rotating motor increases beyond a safelimit. By means of the improved feed control means there is obtainedprotection for the drilling apparatus and an automatic regulation of thefeeding pressure, so that there may be a drilling of the material at amaximum safe rate. Other advantages of the invention will be clearlyapparent torthose skilled in the art.

While there are in this application specifically described several formswhich the invention may assume in practice, it will be understood thatthese forms of the same are shown for purposes of illustration and thatthe invention may be further modified and embodied in Various otherforms without Vdeparting from its spirit or the scope of the appendedclaims.

What I claim as new and desire to secure by Letters Patent is:

1. In a drilling apparatus, in combination, a drill rotating motor,feeding means for said drill rotating motor comprising cooperatingfeeding elements, one of which is rotatable and the other continuouslyheld against rotation, power means the sourceof operating energy forwhich is separate from said drill rotating motor for rotating saidrotatable element, and means responsive to changes in resistance torotation of said drill rotating motor for automatically controlling therotation of said rotatable element.

2. In a drilling apparatus, in combination, a drill rotating motor,feeding means for said drill rotating motor comprising 4cooperatingfeeding elements, Honeof which is rotatablean dv the other continuouslyheld against rotation, .said element continuously held vagainst rotationbeing ,carried by said drill rotating motor'forniovement therewith,power means the source of operating energy Kfor which is separate 'from:said drill .rotating motor for vrotating said rotatable element, `andmeans responsive tochanges rin resistance to Yrotation of .said drill'rotating motor and Aoperative when the resistance exceeds iapredetermined amount for automatically controlling the rotation'of saidrotatableelement. f

3.. In a drilling apparatus, in combination, -a .drill rot-ating motor,ysupporting Y 'and guiding means for said ;motor,means forfeeding-saidmotor along said'supporting and guiding-meanscomprising cooperating-feedi-ng elements, of which one is rotatably mounted,respectively-carried by said motorV and said Supporting and guidingmeans, and-'a feed motor for rotating'said rotatable feeding element,Iand' means responsive to changesl in Vresista-nce to rotationof-said'drill rotating motorand operative when the resistance exceedsa-predetermined-amount for automatically increa-sing the-resistance torotation of said rotatable element.

4. InY a drilling apparatus, in combination, a drill rotating ymotor,supporting and guiding means for said motor, Ymeans-for feeding saidmotoralong said supporting and guiding meanscomprising cooperatingfeeding elements, 4of which oneis rotatably mounted, respectivelycarried by said" motor and said supporting and guiding means, and meanslforcontrolling therateof feed of said motor comprisingbrakedisksrotating with said rotatable feeding elementlandmovablelongitudinally thereof, .brake `disks non-rotatably supported formovement with said motoralong said supporting and guiding means .andinterleaved with said first ymentioned brake disks, andmeans actuated bysaid motor on a predetermined in.- crease in ,load on .the latter `forpressingsaid first and-secondmentioned brake disksinto frictionalengagement with each other.

5, ln a-drilling apparatus,v in combination, a

drill rotating motor, supporting and, guiding means for said `motor,meansA for, feeding said ,motor alongsaid supporting and guiding meanscomprising .cooperating feedingy elements, of whichv one isv rotatablymounted, respectively Carried by Sad motor and said supportingandguiding means, means for rotating said rotatable feeding element, andmeans for controlling the rate of feed of said motor comprising a fricition element rotating with said rotatable feeding element and movablelongitudinally thereof, a friction element non-rotatably supported formovement with said motor along said supporting and guiding means, andmeans actuated bv said motor on a predetermined increase in load on thelatter for pressing said yfriction elements together, thereby resistingrotation of said rotatable feeding element.

6. In a drilling apparatus, in combination, a i

rotary drilling motor for rotating a drill bit, supporting and guidingmeans for saidm'otor, said motor being mounted on said supporting andguiding means for limited rotary movement relative theretdmeans forfeeding said motor along said supporting and rguiding means comprisingfeeding elements, of which one is rotatably mounted, respectivelycarried by said motor and said supporting and guiding means, and meanslfor controlling the rate of feed of said motor 1,0 comprising afriction element rotating with said rotatable feeding element andmovable longitudinally thereof, a friction'element non-rotatablysupported for movement with said motor along said supporting and guidingmeans, and means for pressing said friction elements together includinga member actuated by said motor on rotation of the latter relative tosaid supporting and guiding means.

7. In a drilling apparatus, in combination, a rotary drilling motor forrotating a drill bit', supporting andguiding means for said motor, saidmoto-r being mounted on said supporting and guiding means for limitedrotary movement relative thereto, means for feeding said motor alongsaid supporting .and guiding means comprising feeding elements, of Whichone is rotatably mounted, respectively carried by said motor and saidsupporting rand guiding means, and means for controlling the rate offeed of said motor -comprising a friction element rotating with saidrotatable' feeding element and movable longitudinally thereof, afriction velement non-rotatably supported for movement with said motoralong said supporting and guiding means, and means for pressing saidfriction elements together including a member pivotally connected at oneend to saidmotor supporting means and engaging one of said frictionelements at its other end, and cam means Yiixed to said motor andoperative on rotary movement of said motor relative to said supportingand guiding means due to overloading of the motor forswinging saidpivoted member in a direction to engage said friction elements.

8. In a drilling apparatus, `in combination. a rotary drilling motor forrotating a drill bit, supporting and guiding means for said motor, saidmotor being mounted on said-supporting and guiding means for limitedrotary movement relative thereto, feeding Ameans for said drilling motorcomprising feeding elements, of Whichfone is rotatably mounted,respectively carried by said motor and said supporting and guidingmeans, said feeding elements eifecting feeding of said drilling motor on`relative rotation therebetween,

lmeans for rotating said rotatable element, and

means including` friction elements controlled by the rotary 'movement ofsaid motor relative rto said supporting and guiding means due tooverloading Aof the motor for automatically controlling the rotation ofsaid rotatable feeding element.

'9. In a drilling apparatus, in combination, a drill rotating motor,feeding means for said drill rotating motor comprising cooperatingfeeding elements interengaged IWith each other and one of which isrotatable relative to the other to effect feed, afeed motor for rotatingsaid rotatable element, and means controlled by the 'torque load changeson said -drill rotating motor and operative when the torque load exceedsa predetermined amount for automatically increasing the resistance torotation of said rotatable-element.

l0. In a drilling apparatus, va rotary drilling motor for rotating a-drill bit, motor operated feeding mechanism `for Said drilling motorincluding elements operative on relative rotation to effect feed of saiddrilling motor, means for varying the resistance to rotation of certainof said elements and causing avariation in the relative rotationthereof, and means for actuating said last mentioned means automaticallyvariably in proportion -to excesses in torque above a predeterminedamount exerted by said drilling motor.

11. In a drilling apparatus, in combination, a rotary drilling motor forrotating a drill bit, said rotary drilling motor having one of itselements connected in driving relation with a drill bit and anotherelement, between'which and the first a rotary reaction takes place whensaid motor is running, supported for limited rotary movement, feedingmeans for said motor including cooperating elements coacting on rotationof one of the same to effect motor feed, braking means for said lastmentioned element, and operative connections between said secondmentioned motor element and said braking means for actuating saidvbraking means automatically when an eX- cessive torque is exerted bysaid motor.

12. In a drilling apparatus, in combination, a drill rotating motor,feeding means for said drill rotating motor comprising cooperatingfeeding elements, of which one is rotatably mounted, means for rotatingsaid rotatable feeding element to effect feed, means for resistingrotation of said rotatable element, and means responsive to the loadchanges on said drill rotating motor for controlling said resistingmeans to vary the resistance to rotation of saidl rotatable element,said last mentioned means being operative at predetermined loadincreases on said drill rotating motor for effecting a slowing down ofsaid rotatable element to decrease the rate of feed.

13. In a drilling apparatus, in combination, a drilling motor forrotating a drill bit, feeding means for the drill bit including arotatable feeding element, frictional resistance means for retarding therotation of said rotatable feeding element, and means for automaticallyregulating said frictional resistance means to vary the rate of feed inaccordance with variations in resistance to rotation of the drill bit,

14. In a drilling apparatus, in combination, a drilling motor forrotating a drill bit, feeding means for the drill bit includingrelatively rotatable, coacting feeding elements and a feeding motor foreffecting relative rotation of said elements, said feeding motorconstituting the sole source of power for said feeding means, and meansautomatically responsive to torque load changes on the drill bit forcontrolling the rate of relative rotation between said feeding elementsto vary the rate of feed.

15. In a drilling apparatus, in combination, motor-operated means forrotating a drilling implement for causing the same to effect itsdrilling function, feeding means for the drilling implement comprisingcooperating feeding elements, one of which is rotatable and the othercontinuously held against rotation, power means the source of operatingenergy for which`is separate from said motor-operated means for rotatingsaid rotatable feeding element to effect feed, and means responsive tochanges in resistance to rotation of said implement-rotating-means forautomatically controlling the rotation of said rotatable feedingelement.

16. In a drilling apparatus, in combination, motor-operated means forrotating a drilling implement for causing the same to effect itsdrilling function, feeding means for the drilling implement comprisingcooperating feeding elements, one of which is rotatable and the othercontinuously held against rotation, said element continuously heldagainst rotation being mounted for movement with the drilling implement,power means the source of operating energy for which is separate fromsaid motor-operated means for rotating said rotatable feeding element,and

means responsive to changes in resistance to rotation of saidimplement-rotating-means and operative when the resistance exceeds apredetermined amount for automatically controlling the rotation of saidrotatable element.

1'7. In a drilling apparatus, in combination, motor-operated means forrotating a drilling implement for causing the same to effect itsdrilling function, supporting and guiding means for the drillingimplement, means for feeding the drilling implement along saidsupporting and guiding means comprising cooperating feeding elements, ofwhich one is rotatably mounted and the other is held against rotation,one feeding element adapted to move with the drilling implement and theother carried by said supporting and guiding means and relative to whichthe first is movable, said feeding means operative to effect feeding ofthe drilling implement on relative rotation of said feeding elements,and a feed motor for rotating said rotatable feeding element, and meansresponsive to changes in resistance to rotation of saidimplement-rotating-means and operative when the resistance exceeds apredetermined amount for automatically increasing the resistance torotation of said rotatable feeding element.

18. In a drilling apparatus, in combination, motor-operated means forrotating a drilling irnplement for causing the same to effect itsdrilling function, feeding means for the drilling implement comprisingcooperating feeding elements interengaged with each other and one ofwhich is rotatable relative to the other to effect feed, and a feedmotor for rotating said rotatable feeding element, and means controlledby the torqueload changes on said implement-rotating-ineans andoperative when the toroue load exceeds a predetermined amount forautomatically increasing the resistance to rotation of said rotatablefeeding element.

19. In a drilling apparatus, a motor for rotating a drilling implement,feeding mechanism for the drilling implement includingr elementsoperative on relative rotation to effect feed of the drilling implementand motor operated means for effecting relative rotation of saidelements, means for varying the resistance to rotation of certain ofsaid elements so as to vary the relative rotation thereof, and means foractuating said last mentioned means automatically variably in proportionto excesses in torque above a predetermined amount exerted by saidimplement-rotating-motor.

20. In a drilling apparatus, in combination, motor-operated means forrotating a drilling implement for causing the same to effect itsdrilling function, feeding means for a drilling implement comprisingcooperating feeding elements, of which one is rotatably mounted, meansfor rotating said rotatable feeding element to eifect feed, and meansresponsive to the torque-load changes on said implement-rotating-meansfor varying the resistance to rotation of said rotatable feedingelement, said last mentioned means being operative at predeterminedtorque-load increases on said implement-rotating-means for eifecting aslowing down of said rotatable feeding element to decrease the rate offeed.

21. In a drilling apparatus, the combination comprising motor operatedmeans for rotating a drilling implement, feeding means for the drillingimplement including a torque motor adapted to exert a substantiallyconstant feeding force, and means responsive to torque-load changes onsaid implement-rotating-means for automatically controlling .thetransmission of the feeding forces from said torque motor to thedrilling implement to regulate the rate of feed.

22. In a drilling apparatus, the combination comprising motor operatedmeans for rotating a drilling implement, means for feeding the drillingimplement including relatively rotatable mechanically interengagedfeeding elements, and braking means responsive to torque load changes onsaid implement-rotating-means for automatically controlling the rate ofrelative rotation of said feeding elements to regulate the rate of feed.

23. In a drilling apparatus, the combination comprising motor operatedmeans for rotating a drilling implement, means for feeding the drillingimplement including a torque motor ladapted to exert a substantiallyconstant feeding torque, frictional means for resisting the operation ofsaid torque motor, and means responsive to torque-load changes on saidimplement-rotatingmeans for automatically controlling the loading ofsaid frictional resistance means to regulate the rate of feed.

24. In a drilling apparatus, the combination comprising motor operatedmeans for actuating REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 535,451 Meissner Mar. 12, 18951,087,089 Trotter Feb. 10, 1914 556,502 Hebgen Mar. 17, 1896 FOREIGNPATENTS Number Country Date 229,867 Germany Jan. 10, 1911 243,641Germany Feb. 19, 1912 21,771 Great Britain Oct. 30, 1914

